Sankey diagram is a data visualization tool that can be used to visualize multidimensional data in different ways. Originally, they were used to visual the flow of resources such as energy or material. The important features of Sankey diagrams is that they represent the physical flow from a source to a target related of a unit of measure (e.g., functional unit or period of time) and that the magnitude of the flow is shown by the size of the link. (Lupton and Allwood, 2017)
For project management, Sankey diagrams can be used to show the flow of effort between such topics as companies, roles, and deliverables. The diagram is a Sankey diagram of actual effort for a technology implementation project. It shows how the total project effort is divided by different dimensions (i.e., company, role, deliverable, and capability) and how the effort flows between the different dimensions.
Based on the article a few recommendations for visualization practices in projects, this diagram fits the recommendations as follows:
- Specify your objective for visualization — Demonstrate how effort was spent within the project.
- Make it action-oriented — Not action oriented in print; online each flow can be selected separately and the value of the flow is shown in a tool tip
- Make it messy — N/A
- Make it specific to the situation — this was the real history of the project.
- Use different dimensions — it uses different
- colors, which show effort different sources and targets
- size, flow size is relative to amount of effort
- dimensions: based on columns
- Project role
- Make it interesting — visual way of evaluating project effort
How it was created
The diagram is based on the timecard entries for a specific project considering 1) the person, 2) the roles the people fulfilled, 3) their company. 4) hours worked, and 5) a comment associated with the time entry. The comments were analyzed and assigned to a deliverable and to a capability. The effort was summarized for a three-different source and target columns as follows.
All three summaries were put into one csv file and visualized using d3js Sankey java script. An example of the csv layout is as follows. The source code for java script at the following location.http://bl.ocks.org/d3noob/c9b90689c1438f57d649
Lupton, R. C. & Allwood, J. M. 2017. Hybrid Sankey diagrams: Visual analysis of multidimensional data for understanding resource use. Resources, Conservation and Recycling, 124, 141-151.